Refactor the way that SCM changes are tracked and aggregated in rebaseline.py.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/optimize_baselines.py

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import logging
 import optparse
 
 from webkitpy.common.checkout.baselineoptimizer import BaselineOptimizer
 from webkitpy.layout_tests.controllers.test_result_writer import baseline_name
 from webkitpy.tool.commands.rebaseline import AbstractRebaseliningCommand
@@ skipping 33 matching lines @@
         port_names = tool.port_factory.all_port_names(options.platform)
         if not port_names:
             _log.error("No port names match '%s'", options.platform)
             return
         port = tool.port_factory.get(port_names[0])
         optimizer = BaselineOptimizer(tool, port, port_names, skip_scm_commands=options.no_modify_scm)
         tests = port.tests(args)
         for test_name in tests:
             files_to_delete, files_to_add = self._optimize_baseline(optimizer, test_name)
             for path in files_to_delete:
-                self._delete_from_scm_later(path)
+                self._scm_changes.delete_file(path)
             for path in files_to_add:
-                self._add_to_scm_later(path)
+                self._scm_changes.add_file(path)
         self._print_scm_changes()